I can't speak to hormones as my cancer is triple negative, but I can answer your other questions.
1. Radiation treatments are given 5 days a week for 6 weeks. You will get tattooed and have a walk through treatment right before you start. The treatment itself takes about 5-7 min, the changing and set up can take up to half an hour (after the first week, I instinctively knew how to position myself). The nurses will give ointment to help the area heal (I got hydrophor) but you will still burn and blister after a few weeks, at that point they will show you how to treat and dry the blisters. You will not be able to wear a bra after about 2 weeks - I bought camis with Lycra - and mastectomy bras - I wore long sports bras for almost year, as the band on regular bras hurt.
2. If they will be administering treatment via infusion I recommend you get a port. I waited 8 weeks - big mistake, by veins were rolling, insertion was painful, and both my arms were black and blue.
3. I had a lumpectomy with large margins -I still have some pain in the area two years after the procedure, not very much just occasional per-menstural like pain. Also there is still scar tissue floating around in there.